CN115087803A

CN115087803A - Fuel injector including terminal tab

Info

Publication number: CN115087803A
Application number: CN202080096898.0A
Authority: CN
Inventors: M·梅农; S·威肖莱克
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2019-12-18
Filing date: 2020-12-09
Publication date: 2022-09-20
Anticipated expiration: 2040-12-09
Also published as: US20230011415A1; WO2021122188A1; US12031509B2; CN115087803B; DE112020005329T5

Abstract

A fuel injector assembly includes a valve housing (4), a valve stem (26) disposed in the valve housing (4), surrounding the valve housing (4) and for holding the valve stem (26) in the valve housing (4) Internally displaced magnetic coil (18) and terminal tabs (60). The terminal tab (60) includes a bus bar (62) that provides electrical connection between the magnetic coil (18) and the external connector. Additionally, the terminal lug (60) includes a clip (80) that connects to the busbar (62) at a first end (84) of the clip and to the valve housing (4) at a second end (100) of the clip. The clip (80) includes a sacrificial portion (50) configured to separate, for example by dissolution, when the terminal tab (60) is subjected to an overmolding process. As a result of the overmolding process, the clip is divided into multiple spaced parts.

Description

Fuel injector including terminal tab

Background

A fuel injector for injecting fuel into an internal combustion engine may include a valve housing supporting an injector valve and a magnetic coil surrounding the valve housing and actuating the valve. The magnetic coil is controlled by a controller remote from the fuel injector. The fuel injector includes a bus bar electrically connected to the magnetic coil at one end and providing an electrical connection to the controller at an opposite end. In some fuel injectors, a plastic overmold is used to support the bus bar relative to the valve housing and to seal the bus bar from the environment. Because clips are used to support the bus bar relative to the valve housing during the overmolding process, the overmold may not provide a complete seal between the bus bar and the valve housing. That is, in some fuel injectors, there is a possibility of environmental leakage into the injector and/or around the bus bar near the clip. In some fuel injectors, clips that have been provided with labyrinth seals are intended to minimize or eliminate leakage. However, labyrinth seals disposed on the clip are effective under certain over-molding process conditions, which may not be applicable to all fuel injectors. For example, labyrinth seals provided on clips may not be effective for some relatively short fuel injectors for manufacturing-related reasons, such as the location and orientation of the overmolded plastic injection for the relatively short fuel injectors. In addition, although it is known that an effective seal can be obtained when the tip of the labyrinth is sharp, it is difficult to realize a labyrinth having a sharp tip from the viewpoint of the molding process. Furthermore, to avoid damaging the labyrinth during handling and/or transport, additional measures are required, which increase the cost and complexity of the manufacturing process. Accordingly, it is desirable to provide a fuel injector having an overmold that supports a bus bar and is leak-free regardless of fuel injector size. It is also desirable to provide a clip that secures the bus bar to the fuel injector housing, which facilitates forming a leak-free overmold.

Disclosure of Invention

In some aspects, a terminal tab (terminal blade) for a fuel injector including a valve housing supporting an injector valve, and a magnetic coil surrounding the valve housing and configured to actuate the valve is included. The terminal tab is configured to provide an electrical connection between the magnetic coil and the electrical connector. The terminal tab includes: a conductive bus configured to form an electrical connection with the electrical connector and the magnetic coil; and a clip connected to the bus bar at a clip first end and to the valve housing at a clip second end. The clip includes a sacrificial portion. The sacrificial portion is configured to separate when the terminal tab is subjected to an overmolding process such that the clip is divided into a plurality of portions.

In some embodiments, the sacrificial portion is configured to dissolve when the terminal tab is subjected to an overmolding process. In other embodiments, the sacrificial portion is configured to break when the terminal tab is subjected to an overmolding process.

In some embodiments, the sacrificial portion is disposed between the first end of the clip and the second end of the clip.

In some embodiments, the clip includes an elongated body having a body first end secured to the bus bar and a body second end opposite the body first end. The body first end corresponds to the clip first end. The clip includes a resilient portion configured to surround a portion of the valve housing, the resilient portion corresponding to the clip second end. In addition, the clip includes a bridge connecting the second end of the body to the resilient portion. One of the body and the bridge includes a sacrificial portion.

In some embodiments, the body includes a body mid-portion disposed between the body first end and the body second end. The body mid-portion includes a sacrificial portion.

In some embodiments, the sacrificial portion is a single connecting structure having a cross-sectional dimension in the range of 0.2-0.5 times a cross-sectional dimension of the body.

In some embodiments, the sacrificial portion includes at least two connecting structures, and a cross-sectional dimension of each of the at least two connecting structures has a range of 0.2-0.5 times a cross-sectional dimension of the body.

In some embodiments, the sacrificial portion includes a first connection structure and a second connection structure spaced apart from the first connection structure. Each of the first and second connection structures extends parallel to the clip body longitudinal axis and provides a mechanical connection between the first and second ends.

In some embodiments, the bridge portion includes a sacrificial portion.

In some embodiments, a dimension of the bridge in a direction parallel to the longitudinal axis of the valve housing is smaller than a dimension of the resilient portion in a direction parallel to the longitudinal axis of the valve housing.

In some embodiments, the bridge including the sacrificial portion is connected to the resilient portion along an edge of the resilient portion.

In some embodiments, the body includes a body longitudinal axis extending between the body first end and the body second end. The body is elongated along a body longitudinal axis. The body longitudinal axis extends parallel to the longitudinal axis of the valve housing, and the bridge extends in a direction perpendicular to the body longitudinal axis.

In some embodiments, the bus bar has a bus bar first end and a bus bar second end, and the clip body first end is secured to the bus bar at a location disposed between the bus bar first end and the bus bar second end.

In some embodiments, the clip comprises two sacrificial portions.

In some aspects, a fuel injector assembly comprises: a valve housing; and a valve stem disposed in the valve housing and movable relative to an inner surface of the valve housing along a valve housing longitudinal axis. The fuel injector assembly includes: a magnetic coil surrounding the valve housing for actuating the valve stem; and a terminal tab configured to provide an electrical connection between the magnetic coil and an external connector. The terminal tab includes: a conductive bus configured to form an electrical connection with the external connector and the magnetic coil; and a clip connected to the bus bar at a clip first end and to the valve housing at a clip second end. The clip includes a sacrificial portion. The sacrificial portion is configured to separate when the terminal tab is subjected to the overmolding process, such as by dissolving or breaking, such that the clip is divided into a plurality of portions.

In some embodiments, the clip includes an elongated body having a body first end secured to the bus bar and a body second end opposite the body first end. The body first end corresponds to the clip first end. The clip includes a resilient portion configured to surround a portion of the valve housing, the resilient portion corresponding to the clip second end, and a bridge connecting the body second end to the resilient portion. One of the body and the bridge includes a sacrificial portion.

In some embodiments, the bridge portion includes a sacrificial portion.

In some embodiments, the clip comprises two sacrificial portions.

In some embodiments, the fuel injector assembly includes an overmold surrounding the clip and a portion of the bus bar. The overmold and the clip are formed from the same material.

In some embodiments, the fuel injector assembly includes an overmold surrounding the clip and a portion of the bus bar. The overmold is formed from a first material and the clip is formed from a second material. The second material has a melting temperature less than or equal to the melting temperature of the first material.

In some aspects, a method of manufacturing a fuel injector is disclosed. The method comprises the following method steps: providing a partially assembled fuel injector comprising a valve housing, a valve stem movable within the valve housing, and a magnetic coil surrounding the valve housing; providing a terminal tab, the terminal tab comprising: a conductive bus configured to form an electrical connection with an electrical connector and the magnetic coil; and a clip connected to the busbar at a clip first end and to the valve housing at a clip second end, the clip including a sacrificial portion configured to separate, for example by dissolving, when the terminal tab is subjected to an overmolding process; securing the terminal tab to the valve housing using the clip; electrically connecting the bus bar to the magnetic coil; and overmolding the terminal tab and the valve housing portion with a plastic coating such that the portions are enclosed and the sacrificial portion is separated.

In some embodiments, the step of overmolding the terminal tabs and the valve housing portion comprises: the portion is encased in a plastic coating using an injection molding process, and the plastic coating and the clip are formed of the same material.

In some embodiments, the step of overmolding the terminal tabs and the valve housing portion comprises: the portion is encased in a plastic coating using an injection molding process. The plastic coating is formed from a first material, the clip is formed from a second material, and the second material has a melting temperature less than or equal to the melting temperature of the first material.

In some embodiments, the step of overmolding the terminal tabs and the valve housing portion with a plastic coating comprises: injecting plastic into a mold around a portion of the fuel injector including the clip, and the direction of injection of the plastic into the mold is perpendicular to a longitudinal axis of the valve housing.

In some aspects, a terminal tab for a fuel injector assembly includes a sacrificial portion that melts, dissolves, or is otherwise removed during a manufacturing process step in which an overmold is applied to the fuel injector assembly. As a result, the overmold supporting the bus bar relative to the fuel injector housing and providing the electrical connector housing also forms a leak-free seal relative to the valve housing of the fuel injector, thereby preventing moisture from contacting the bus bar.

A method of manufacturing a fuel injector using the terminal tab with the sacrificial portion is also described.

In some aspects, a self-supporting electrical conductor includes: the device includes a conductive element configured to electrically connect a first electrical component to a second electrical component, and a clip configured to support the element relative to the device. The clip includes a clip first end connected to the element, a clip second end configured to be mounted on the device, and a sacrificial portion disposed between the clip first end and the clip second end. An overmold encapsulates the clip and at least a portion of the element. Furthermore, the sacrificial portion is configured to separate when the self-supporting electrical conductor is subjected to an overmolding process to provide an overmold, such as by dissolving or breaking, which separation occurs such that the clip is divided into a plurality of portions.

Drawings

FIG. 1 is a perspective view of a fuel injector assembly.

FIG. 2 is a cross-sectional view of the fuel injector assembly as seen along line 2-2 of FIG. 1.

Fig. 3 is a perspective view of the terminal blade.

Fig. 4 is a side view of the terminal tab of fig. 3.

Fig. 5 is a perspective cross-sectional view of the terminal blade of fig. 3 as seen along line 5-5 of fig. 4.

Fig. 6 is an exploded perspective view of the terminal tab of fig. 3.

Fig. 7 is a perspective view of an alternative embodiment terminal tab.

Fig. 8 is a side view of the terminal tab of fig. 7.

Fig. 9 is a perspective cross-sectional view of the terminal blade of fig. 7 as seen along line 9-9 of fig. 7.

Fig. 10 is a perspective cross-sectional view of the terminal tab of fig. 7 as seen along line 10-10 of fig. 8.

Fig. 11 is a perspective view of another alternative embodiment terminal blade.

Fig. 12 is a side view of the terminal tab of fig. 11.

Fig. 13 is an end view of the terminal tab of fig. 11 with the bus bar omitted.

Fig. 14 is a perspective cross-sectional view of the terminal blade of fig. 11 as seen along line 14-14 of fig. 12.

FIG. 15 is a flow chart illustrating a method of manufacturing a fuel injector.

Fig. 16 is a schematic view of the fuel injector prior to the over-molding step of the terminal tab, with the sacrificial portion in the clip body.

Fig. 17 is a schematic view of the fuel injector of fig. 16 after an overmolding step, wherein the overmold is omitted and showing the terminal tab being separated into two spaced apart portions.

Fig. 18 is a schematic view of the fuel injector prior to the over-molding step of the terminal tabs, with the sacrificial portion in the clip bridge.

Fig. 19 is a schematic view of the fuel injector of fig. 18 after an overmolding step, wherein the overmold is omitted and showing the terminal tab being separated into two spaced apart portions.

Detailed Description

Referring to fig. 1-6, a fuel injector 2 is part of a fuel injection system for injecting fuel into an internal combustion engine (not shown). For example, the fuel injector 2 may be a high pressure device for direct injection into a cylinder of a gasoline engine. The fuel injector 2 may comprise an elongated, substantially tubular valve housing 4 supporting the injector valve 9, and a solenoid 16 surrounding the valve housing 4 and actuating the valve 9. The terminal tab 60 is used to provide an electrical connection between the solenoid 16 and an external connector (not shown). The terminal tab 60 includes a conductive bus bar 62 and a clip 80. The bus bar 62 provides an electrical connection between the solenoid and the connector, while the clip 80 mechanically supports the bus bar 62 in a desired position relative to the valve housing 4 during manufacture and assembly of the fuel injector 2. The fuel injector 2 includes an electrically insulating overmold 40 for holding the bus bar 62 in a desired position relative to the valve housing 4 after manufacture and assembly. Clip 80 includes a sacrificial portion configured to separate during the process of forming overmold 40, whereby clip 80 is divided into physically spaced bus portions 61 and clip portions 81. Due to the separation of the sacrificial portion 50 and the separation of the clip 80 into the two separate portions 61, 81, the overmold 40 effectively surrounds the bus bar 62 and portions of the valve housing 4 and seals the bus bar 62 from the environment, as discussed further below.

The valve housing 4 is of elongate, generally tubular construction. The first end 6 of the valve housing 4 provides a fuel connection fitting 10 and the second opposite end 8 of the valve housing 4 provides a valve seat 12 and an opening (not shown). The inner surface of the valve housing 4 defines a fuel conduit 14 extending between the fuel connection fitting 10 and the valve seat 12.

The solenoid 16 includes a magnetic coil 18 wound on a bobbin and a magnetic sleeve 20 surrounding the magnetic coil 18. The magnetic sleeve 20 is fixed to the outer surface of the valve housing 4 at a position disposed between the connection fitting 10 and the valve opening provided in the valve seat 12. The armature 24 is movable along a longitudinal axis 38 of the valve housing 4 in response to the magnetic coil 18 and is permanently connected to the valve needle 26, which is in turn connected to the ball 9a of the valve 9.

The overmold 40 is formed of an electrically insulating material, such as plastic, and includes an annular portion 42 surrounding a circumferential portion of the valve housing 4 at a location between the magnetic sleeve 20 and the connection fitting 10, and a connector portion 44 projecting outwardly from the annular portion 42. The connector portion 44 includes a shroud 46 surrounding a first end 68 of the bus bar 62 and is configured to receive an external connector therein. When the external connector is received within the connector shroud 46, an electrical connection is provided between the magnetic coil 18 and an electronic control unit (not shown). The electronic control unit controls the magnetic coil 18 and thus also the fuel dispensing from the fuel injector 2.

Referring to fig. 3-6, the terminal tab 60 including the bus bar 62 and the clip 80 is used during manufacturing of the fuel injector 2 to secure the bus bar 62 relative to the valve housing 4 during manufacturing method steps that are performed before the overmold 40 has been applied. The bus bar 62 includes a pair of electrically

conductive pins

64, 66 and electrically insulating brackets 78 that hold the

pins

64, 66 in a parallel, spaced apart configuration. Each

64, 66 includes a pin first end 68 disposed in the connector shroud 46, a pin second end 70 opposite the pin first end 68, and a pin intermediate portion 72 disposed between the pin first end 68 and the pin second end 70. In the illustrated embodiment, the

pins

64, 66 are elongated and include a first bend 74 disposed between the pin intermediate portion 72 and the pin first end 68 and a second bend 76 disposed between the intermediate portion 72 and the pin second end 70. The first bend 74 is in a direction opposite to the direction of the second bend 76, whereby each

64, 66 generally has a Z-shape when the busbar 62 is viewed in side elevation (fig. 4). Bracket 78 engages pin intermediate portion 72 at a location adjacent first bend 74.

The clip 80 is free of labyrinth seals and includes an elongated body 82 secured to the bus bar 62, a resilient portion 100 forming a mechanical connection with the valve housing 4, and a bridge 120 extending between the body 82 and the resilient portion 100 and mechanically connecting the body 82 to the resilient portion 100.

The clip body 82 has a generally cylindrical shape and includes a body first end 84 and a body second end 86 opposite the body first end 84. The body first end 84 is also referred to herein as a clip first end. The body 82 includes a body mid-portion 88 disposed between the body first end 84 and the body second end 86. Further, the body 82 includes a longitudinal axis 90 passing through the body first end 84, the body intermediate portion 88, and the body second end 86. The body first end 84 is overmolded onto the intermediate portion 72 of the bus bar 62 at a location adjacent the second bend 76. The body first end 84 is overmolded onto the bus bar 62 such that the body 82 is secured to the bus bar intermediate portion 72 and the bus bar intermediate portion 72 extends in a direction perpendicular to the body longitudinal axis 90. In this configuration, the busbar first end 68 overlies the body 82 and is angled relative to the body longitudinal axis 90. Further, the bus bar second end 70 projects in a direction away from the body 82 in a direction generally parallel to the body longitudinal axis 90.

The resilient portion 100 is an arcuate band 102 that encircles a portion of the circumferential portion of the valve housing 4. The band 102 includes a first end 104, a second end 106, and an intermediate portion 108 disposed between the first and second ends 104, 106. The resilient portion 100 has resilient properties, extends over an arc length of more than 180 degrees and less than 270 degrees, and is dimensioned to grip the outer surface of the valve housing 4. With this configuration, the clip 80 is elastically held in a desired position with respect to the valve housing 4. At each of the first and second ends 104, 106, an outwardly facing surface 110 of the band 102 includes a protrusion 112 that provides a key for engagement with the overmold 40. The resilient portion 100 is also referred to herein as the clip second end.

The bridge 120 is a rigid structure that extends between the resilient portion intermediate portion 108 and the body second end 86 and provides a mechanical connection, the bridge 120 including a first end 122 connected to the body 82, a second end connected to the resilient portion 100, and an intermediate portion 126 disposed between the bridge first end 122 and the bridge second end 124. The bridge 120 is integrally formed with the resilient portion 100 and the body 82 and extends in a direction perpendicular to the body longitudinal axis 90. As a result, the bridge 120 serves to offset the body 82 from the valve housing 4 in a direction perpendicular to the valve housing longitudinal axis 38. In other words, the bridge 120 serves to offset the body 82 from the valve housing 4 in a radially outward direction relative to the outer surface of the valve housing 4.

The bridge 120 is generally rectangular in shape and has a length dimension extending parallel to the body longitudinal axis 90, a height dimension extending perpendicular to the body longitudinal axis 90 and parallel to a radius of the valve housing 4, and a width dimension extending perpendicular to the body longitudinal axis 90 and the radius of the valve housing 4. When the clip 80 is viewed in side elevation (e.g., in the direction of arrow 48 of fig. 6), the bridge 120 has a length dimension equal to the corresponding dimension of the band 102 of the resilient portion 100. When the clip 80 is viewed in end view (e.g., in the direction of arrow 36 of fig. 6), the bridge 12 has a uniform width dimension along its height dimension.

In the illustrated embodiment, the clip 80 and the bracket 78 are formed of the same material, e.g., an insulating material such as plastic, while the

pins

64, 64 are formed of a conductive material such as metal.

The clips 80 of the terminal tabs 60 serve to maintain the bus bars 62 in a desired orientation and position relative to the valve housing 4 during the manufacturing step prior to the overmolding step where overmolding is applied to the valve housing 4. For example, in some embodiments, the clip 80 supports the bus bar 62 during a welding step of an injector manufacturing process that welds the bus bar second end 70 to the magnetic coil 18. Once the weld has been achieved, the position of the bus bar 62 is fixed relative to the fuel injector 2 and the clip 80 is no longer required. In view of the fact that clip 80 is not required to position and stabilize bus bar 62 after the welding step, clip 80 includes sacrificial portion 50 that is separated during the process of forming overmold 40. In this embodiment, the sacrificial portion dissolves during the overmolding process. As the sacrificial portion 50 dissolves during the overmolding process, the clip 80 is divided into the physically spaced bus bar portions 61 and the clip portions 81 (fig. 19). By dividing the clip 80 into two separate portions 61, 81, the overmold 40 can effectively surround the bus bar 62 and portions of the valve housing 4 and seal the bus bar 62 from the environment.

In the embodiment shown in fig. 3-6, the body mid-portion 88 provides the sacrificial portion 50. To this end, the body intermediate portion 88 (e.g., the sacrificial portion 50) is a structure having a reduced diameter relative to the body first and second ends 84, 86. For example, in the illustrated embodiment, the sacrificial portion 50 has a cross-sectional dimension in the range of 0.2-0.5 times a cross-sectional dimension of the respective body first and second ends 84, 86.

In some embodiments, sacrificial portion 50 is a rigid rod 92 of uniform diameter extending between and physically connecting body first end 84 and body second end 86. Shoulders 96, 98 are provided at the diameter transitions between the sacrificial portion 50 and the respective body first and second ends 84, 86. In other embodiments, the transition between the sacrificial portion 50 and the respective body first and second ends 84, 86 may be rounded. In the illustrated embodiment, the sacrificial portion 50 is concentric with the clip body 82.

The diameter of the sacrificial portion 50 is set such that during the overmolding process, when the plastic used to form the overmold 40 is injected at high pressure near the terminal tabs 60, the sacrificial portion 50 dissolves and/or otherwise breaks due to the temperature and/or mass flow of the plastic.

Referring to fig. 7-10, an alternative embodiment of terminal tab 160 will now be described. The terminal tab 160 of fig. 8-10 is similar to the terminal tab 60 of fig. 3-6, and common reference numerals are used to identify common elements. The terminal tab 160 of fig. 7-10 differs from the terminal tab 60 of fig. 3-6 in that the sacrificial portion 150 includes a pair of rigid rods 92, 94 of uniform diameter extending between the body first end 84 and the body second end 86. In the illustrated embodiment, the rods 92, 94 extend parallel to each other and to the body longitudinal axis 90. The rods 92, 94 are arranged to overlap each other when the fuel injection is viewed in side view. In other words, both rods 92, 94 lie in a common plane extending radially from the valve housing longitudinal axis 38. The rods 92, 94 are spaced apart. In the illustrated embodiment, the rods 92, 94 are spaced apart as far as possible along the diameter of the body 82. Additionally, the cross-sectional dimension of each rod 92, 94 is in the range of 0.2-0.5 times the cross-sectional dimension of the respective body first and second ends 84, 86. During the overmolding process, when the plastic used to form the overmold 40 is injected at high pressure near the terminal tabs 160, the sacrificial portion 150 dissolves and/or otherwise breaks due to the temperature and/or mass flow of the plastic.

Referring to fig. 11-14, another alternative embodiment of the terminal tab 260 will now be described. The terminal tab 260 of fig. 11-14 is similar to the terminal tab 60 of fig. 3-6, and common reference numerals are used to identify common elements. Terminal tab 260 of fig. 11-14 differs from terminal tab 60 of fig. 3-6 in that bridge intermediate portion 126 provides sacrificial portion 250. To this end, the bridge intermediate portion 126 (e.g., the sacrificial portion 250) has a reduced diameter relative to the bridge first and second ends 122, 124. In particular, when the clip 80 is viewed in side elevation (fig. 12), the bridge 120, including the sacrificial portion 250, has a length dimension that is less than a corresponding dimension of the band 102 of the resilient portion 100. The bridge 120 including the sacrificial portion 250 is connected to the resilient portion 100 along the inner edge 114 of the resilient portion 100. In the illustrated embodiment, the bridge length dimension is in the range of 0.25 to 0.75 times the length dimension of the band 102. When the clip 80 is viewed in end view (fig. 13), the bridge 120 has a non-uniform width dimension along its height dimension. As shown, the sacrificial portion 250 is shaped such that the transition between the sacrificial portion 250 and the respective bridge first and second ends 122, 124 is rounded. In some embodiments, the bridge intermediate portion 126 has a cross-sectional dimension in the range of 0.4-0.8 times the cross-sectional dimension of the respective bridge first and second ends 122, 124. During the overmolding process, when the plastic used to form the overmold 40 is injected at high pressure near the terminal tabs 260, the sacrificial portions 250 dissolve and/or otherwise break due to the temperature and/or mass flow of the plastic. For example, due to the relative thickness of sacrificial portion 250, sacrificial portion 250 may not dissolve completely, but may separate due to material flow during the injection of material into the mold. In this example, the flowable material may push the resilient portion 100 such that the sacrificial portion 250 separates via a bending or tensile force.

Referring to fig. 15, a method of manufacturing the fuel injector 2 using the terminal tab 60 will now be described. The method provides a fuel injector 2 in which the overmold 40 forms a leak-free seal with respect to the valve housing 4, thereby preventing moisture from contacting the bus bar 62. In the method, as an initial step, a partially assembled fuel injector is provided that includes a valve housing, a valve stem movable within the valve housing, a magnetic coil surrounding the valve housing, and other auxiliary structures (step 200). Additionally, terminal tabs 60 are provided (step 202), wherein the clips 80 include the sacrificial portion 50. The terminal tab 60 is secured to the valve housing 4 by attaching the resilient portion 100 to the outer surface of the valve housing 4 at a location between the magnetic coil 18 and the valve housing first end 6 (step 204). When the terminal tab 60 is secured to the valve housing 4, the bus bar 62 is arranged such that the second end 70 of each

64, 66 of the bus bar 62 is adjacent a portion of the magnetic coil 18 and the first end 68 of each

64, 66 of the bus bar 62 covers the clip body 82. In this configuration, the first end 68 of each

64, 66 is spaced from the valve housing outer surface and extends toward the valve housing first end 6.

After the terminal tab 60 is secured to the valve housing 4, the method includes electrically connecting the bus bar 62 to the magnetic coil 18 (step 206). For example, in some embodiments, the second end 70 of each

64, 66 is welded to a portion of the magnetic coil 18. As previously described, once the weld has been made, the position of the bus bar 62 is fixed relative to the fuel injector 2 and the clip 80 is no longer required.

After the step of electrically connecting the bus bar 62 to the magnetic coil 18, the terminal tab 60 and portions of the valve housing 4 are overmolded with a plastic coating (step 208). As a result of this step, the plastic overmold 40 is formed on the valve housing 4. In particular, the annular portion 42 surrounds the circumferential portion of the valve housing 4 at a location adjacent the solenoid 16 such that the busbar second end 70 and the busbar intermediate portion 72, including the weld, are encased in plastic. The bus bar first end 68 is exposed, but is surrounded by the shroud 46 of the connector portion 44. In addition, the entire clip 80 is encased in a plastic coated annular portion.

In some embodiments, the overmold is implemented using an injection molding process. During the injection molding process, the plastic used to form the overmold 40 is injected into an overmolding tool (not shown) that surrounds the valve housing 4 and the terminal tabs 60. The plastic is melted and injected under high pressure into the overmolding tool in a direction perpendicular to the valve housing longitudinal axis 38 at a location generally aligned with the clip body 82 and/or the bridge portion 120. Thus, during injection molding of the plastic, the molten plastic flows toward the clip 80 and then around the clip 80. In the illustrated embodiment, the material used to form clip 80 is the same as the material used to form overmold 40, and thus the melting temperature of clip 80 is the same as the melting temperature of overmold 40. The presence of the molten overmolded plastic causes the sacrificial portion 50 to melt when the molten overmolded plastic is injected around the body mid-portion 88. In addition, the flow of the high pressure injection material exerts pressure on the sacrificial portion 50, which facilitates the dissolution of the sacrificial portion. Due to the dissolution of the sacrificial portion 50, the clip 80 is divided into two separate portions 61, 81. The space previously occupied by the sacrificial portion 50 becomes occupied by the overmold material, allowing the overmold 40 to effectively surround the bus bar 62 and portions of the valve housing 4 and seal the bus bar 62 from the environment.

The result of the dissolution of the sacrificial portions 50, 150 of the

terminal tabs

60, 160 is shown schematically in fig. 16 and 17. In the

terminal tabs

60, 160, the sacrificial portions 50, 150 are disposed in the clip body intermediate portion 88. After the overmolding step, the sacrificial portions 50, 150 are no longer present and the

terminal tabs

60, 160 are separated into physically spaced bus bar portions 61 and clip portions 81. As seen in fig. 17, the bus bar portion 61 includes a bus bar 62 and a clip body first end 84, while the clip portion 81 includes a clip body second end 86, a bridge 120, and a resilient portion 100.

The result of the dissolution of the sacrificial portion 250 of the terminal tab 260 is schematically illustrated in fig. 18 and 19. In terminal tab 260, sacrificial portion 250 is disposed in bridge intermediate portion 126. After the overmolding step, the sacrificial portion 250 is no longer present and the terminal tab 160 is separated into a physically spaced apart bus portion 261 and a clip portion 281. As shown in fig. 20, the bus bar portion 261 includes the bus bar 62, the clip body 82, and the bridge first end 122, while the clip portion 281 includes the bridge second end 124 and the resilient portion 100.

Although in the illustrated embodiment, the plastic material used to form overmold 40 is the same as the plastic material used to form clip 80, fuel injector 2 is not limited to this configuration. For example, in some embodiments, overmold 40 is formed from a first material and clip 80 is formed from a second material. The melting temperature of the second material is less than or equal to the melting temperature of the first material to facilitate melting of the sacrificial portion 50 during the overmolding step. When the second material used to form clip 80 has a lower melting temperature than the first material used to form overmold 40, support 78 is advantageously formed from the same material as the first material or has a higher melting temperature than the first material.

Although in the illustrated embodiment, the clip 80 includes a single sacrificial portion 50, 150, 250, which may be disposed at either the body 82 or the bridge 120, it is contemplated that the clip 80 may include more than one sacrificial portion, such as including a sacrificial portion at each of the body 82 and the bridge 120. Further, the location of the sacrificial portions 50, 150, 250 is not limited to the intermediate portion 88 of the clip body 82 or the intermediate portion 126 of the bridge 120. Rather, the sacrificial portions 50, 150, 250 may be located anywhere along the clip 80 as long as the sacrificial portions 50, 150, 250 do not contact the bus bar 62. The location and geometry of the sacrificial portions 50, 150, 250 is determined by the overmolding tool and the final overmolding process.

Although the terminal tabs with sacrificial portions are shown herein with respect to providing an electrical connection between the solenoid and an external connector of the fuel injector, the terminal tabs are not limited to this application. For example, in some embodiments, self-supporting electrical conductors may be used to provide electrical connections. In particular, the self-supporting electrical conductor comprises an electrically conductive element configured to electrically connect the first electrical component to the second electrical component. The self-supporting electrical conductor includes a clip configured to support the element relative to the device. The clip has a sacrificial portion disposed between opposite ends of the clip. In addition, the self-supporting electrical conductor has an overmold that encapsulates the clip and at least a portion of the element. As in the previous embodiments, the sacrificial portion is configured to separate when the self-supporting electrical conductor is subjected to an overmolding process to provide an overmold, and the separation occurs such that the clip is divided into a plurality of portions.

Alternative illustrative embodiments of fuel injector assemblies including terminal tabs and methods of making fuel injectors are described above in greater detail. It should be understood that only so much of the structure has been described herein as is deemed necessary to illustrate certain features of the assemblies and methods. Other conventional structures and the attendant and ancillary components of the assemblies and methods are presumed to be known and understood by those skilled in the art. Further, while working examples of the assembly and method have been described above, the assembly and method are not limited to the working examples described above, but various design changes may be made without departing from the terminal tab, fuel injector assembly, and method set forth in the claims.

Claims

1. A terminal lug for a fuel injector comprising a valve housing supporting an injector valve and a magnetic coil surrounding the valve housing and configured to actuate the valve, the terminal A tab is configured to provide an electrical connection between the magnetic coil and the electrical connector, and the terminal tab includes:

a conductive busbar configured to form electrical connection with the electrical connector and the magnetic coil; and

a clip connected to the busbar at a first end of the clip and to the valve housing at a second end of the clip, the clip including a sacrificial portion configured to be connected when the terminal is connected The pieces are separated as they undergo the overmolding process, so that the clip is divided into multiple parts.

2. The terminal tab of claim 1, wherein the sacrificial portion is configured to dissolve when the terminal tab undergoes an overmolding process.

3. The terminal lug of claim 1, wherein the clip comprises:

an elongated body having a first end of the body secured to the busbar and a second end of the body opposite the first end of the body, the first end of the body corresponding to the first end of the clip,

a resilient portion configured to surround a portion of the valve housing, the resilient portion corresponding to the second end of the clip, and

a bridge portion connecting the second end of the body to the elastic portion,

And wherein one of the body and the bridge includes the sacrificial portion.

4. The terminal lug of claim 3, wherein the body includes a body intermediate portion disposed between the body first end and the body second end, and wherein the body intermediate portion includes the body intermediate portion. sacrifice part.

5. The terminal tab of claim 4, wherein the sacrificial portion is a single connection structure having a cross-sectional dimension in the range of 0.2-0.5 times the cross-sectional dimension of the body.

6. The terminal tab of claim 4, wherein the sacrificial portion includes at least two connection structures, and each of the at least two connection structures has a cross-sectional dimension of 0.2 of the cross-sectional dimension of the body -0.5 times the range.

7. The terminal tab of claim 4, wherein the sacrificial portion comprises a first connection structure and a second connection structure spaced apart from the first connection structure, the first connection structure and the first connection structure Each of the two connecting structures extends parallel to the clip body longitudinal axis and provides a mechanical connection between the first end and the second end.

8. The terminal tab of claim 3, wherein the bridge portion includes the sacrificial portion.

9 . The terminal tab of claim 8 , wherein the bridge portion has a smaller dimension in a direction parallel to the longitudinal axis of the valve housing than the elastic portion is in a direction parallel to the longitudinal axis of the valve housing. 10 . Dimensions in the direction of the axis.

10. The terminal tab of claim 8, wherein a bridge including the sacrificial portion is connected to the spring portion along an edge of the spring portion.

11. The terminal lug of claim 3, wherein:

the body includes a longitudinal axis of the body extending between the first end of the body and the second end of the body,

The body is elongated along a longitudinal axis of the body,

the body longitudinal axis extends parallel to the valve housing longitudinal axis, and

The bridge portion extends in a direction perpendicular to the longitudinal axis of the body.

12. The terminal lug according to claim 3, wherein the bus bar has a bus bar first end and a bus bar second end, and the clip body first end is disposed between the bus bar first end and the bus bar Secured to the busbar at a location between the second ends.

13. A fuel injector assembly comprising:

valve housing;

a valve stem disposed in the valve housing and movable relative to an inner surface of the valve housing along a valve housing longitudinal axis,

a magnetic coil surrounding the valve housing and for actuating the valve stem; and

a terminal lug configured to provide an electrical connection between the magnetic coil and an external connector, the terminal lug comprising:

a conductive busbar configured to form electrical connection with the external connector and the magnetic coil; and

14. The fuel injector assembly of claim 13, wherein the sacrificial portion is configured to dissolve when the terminal tab is subjected to an overmolding process.

15. The fuel injector assembly of claim 13, wherein the clip comprises:

a bridge portion connecting the second end of the body to the elastic portion,

And wherein one of the body and the bridge includes the sacrificial portion.

16. The fuel injector assembly of claim 15, wherein the body includes an intermediate body portion disposed between the first end of the body and the second end of the body, and wherein the intermediate body portion includes the the sacrifice part.

17. The fuel injector assembly of claim 15, wherein the bridge portion includes the sacrificial portion.

18. The fuel injector assembly of claim 13, comprising an overmold surrounding the clip and a portion of the busbar, the overmold and the clip made of the same material formation.

19. The fuel injector assembly of claim 13, comprising an overmold surrounding the clip and a portion of the busbar, the overmold being formed of a first material, and The clip is formed of a second material, and the second material has a melting temperature that is less than or equal to the melting temperature of the first material.

20. A self-supporting electrical conductor comprising:

a conductive element configured to electrically connect the first electrical component to the second electrical component;

A clip configured to support the element relative to the device, the clip comprising:

connected to the first end of the element's clip,

the second end of the clip is configured to be mounted on the device, and

a sacrificial portion disposed between the first end of the clip and the second end of the clip; and

an overmold enclosing the clip and at least a portion of the element,

in

The sacrificial portion is configured to separate when the self-supporting electrical conductor is subjected to an overmolding process to provide an overmold, the separation occurring such that the clip is separated into a plurality of parts.